The duo spent a lot of time with the singers to learn more about them to play the roles. Stewart told me she admires and respects Joan a lot and that made it much more intense for her. Both Stewart and Fanning also loved the movie's edgy, '70s-style wardrobe, telling me that almost every day the wardrobe department would have something new and crazier for them to wear and they loved it!

This morning the studio released a teaser poster for The Runaways. You can see a big version of the poster, which has the tagline "It's 1975 and they're about to explode," here.